Are people even arguing though that redistribution in general is bad? Isn't it more that 100% is too extreme? Yes it would obviously redistribute wealth, but not without negative side-effects -> a lower rate would achieve redistribution as well (to a lesser extent, by definition) but without less negative side effects.
I take your point that those most 'useful' to society are those most likely to be least deterred by a 100% tax, but do you not think that a great deal of people WILL be deterred, perhaps even a majority (esp. in other areas which ARE still productive though perhaps not as 'useful.')
No. If you know someone who makes $600,000 a year, and you make $60,000, chances are you instinctively see him as a very rich person, someone who might make a million dollars one day, someone beyond your status, making the kind of money you could not make. Now imagine if salaries are capped at $300,000 a year. All of a sudden you know more people who are making the maximum amount of money possible. That is far more likely to influence the average Joe to try and make more money: being rich is no longer being Steve Jobs, Bill Gates, Mark Zuckerberg, or some other famous dude, being rich is now just a question of making as much money as your neighbor Bob. You'd see more people actively try to make more, innovate, start a small side business, provide some services, etc., because suddenly being rich seems far more accessible to the average worker. So purely from an incitative consideration, it would probably incite more people to get richer.
That being said, it would also slow salary growth, as a CEO would obviously still be the one with the highest salary in a company or at least part of the few making the biggest salaries, it would prevent employees below him to see their salaries rise quickly to his level. But this is not a problem, since regulation of wealth accumulation would lead to better living standards for all as governments would have more money to spend on mass transit, parks, public pools, health services, education, the environment, unemployment benefits, etc.
So on one hand,
you have an upward interest in making more money, and on the other
you have a lessened need to make more money. Making more money in such a scenario is no longer a matter of
survival, but a matter of being
creative and having a
desire to experience new things, which is excellent for economic progress and innovation as the economy no longer responds almost exclusively to a need to sustain society but rather to help it thrive and renew itself. Since most people have different desires, the economy grows more broadly than when it grows mostly to sustain everyone's basic needs, which are in general similar.
So with regulation of wealth accumulation, you actually end up with a much more dynamic growth and increased economic stability, all the while the human condition improves as a whole.